1960 40 hp Johnson surging

Hello, I am new here and have a question about my motor maybe some one could help. Okay I just picked up this boat ,I had to replace the harness, battery and battery cables do to some one at midnite auto sales. After that repair I was trying to start it and noticed that a very lot of fuel spilling out from the carb I found some where on one of the forums how to adjust the carb. Well I put it in the lake ran like crap sputtering and stalling (flooding out)with no power. I got home checked the point's cleaned and re-gaped ,re-gaped plugs, took off the carb and cleaned and adjusted the float, that is I flipped the carb over and looking at float made it so it was sitting just above level.re-adjusted high ,low mixture again. Took it out on the lake again started right up ran great . I then tried to adjust the carb in 1/8 turn in. Then the engine started surging no power sputtering all most like some one turning key on and off. Could it be a bad coil or fuel pump or maybe the points out of gap again . I am at whits end, maybe I did some thing or not ,hopefully some one else can point out to me .

Put a timing light on it and check how the plugs are firing -----------Intermittant flash on the light means ignition problems.

Well today I replaced the spark plug cables and re-adjusted the points . Put it in the lake and same thing surging like crazy,took it home. I then took the fuel pump apart to see if the diafram was ripped but it was not. I think tomorrow I will go and purchase new points and condensers and plugs, this way I no it's all new.

When the surging has occured for a few minutes, shut the engine down and use your hand to feel for a difference in cylinder head temperature between the upper and lower cylinders. A difference in temperature usually indicates a mis-firing cylinder caused by a bad coil, condensor, point set, plug or plug wire. A compression test would also indicate any internal problems. Surging caused by fuel related problem can be diagnosed by filling a squirt can with 50 to one mix and squirting it into the carburetor as the surging occurs. If the engine speeds up, it is starving for fuel. Common causes of this are a clogged fuel filter, bad o-rings on the fuel lines, a clogged carburetor, a bad fuel line etc.

Hello bobbyc, I went and ordered new points and condensers while waiting for the parts . I replaced both spark plug wire ,and a new clear view inline fuel filter. I put in the inline fuel filter so I could see the fuel flow and also because there is no filter on the engine. I say that because I think the prior owner put an after market fuel pump in. I cleaned every thing under the flywheel and made sure that there was good connections. I followed the fuel line and where it was connected I cut it back to make sure there was a good connection (there was plenty of room on the lines) put new clamps on. I had my son crank the engine and found it has great spark. I also put new O-rings in the carb needles to tighten them up a little and re-adjusted. I was going to take it out on the lake today and see how she runs but weather was not with me we'll see what tomorrow brings.

Hello guys, Well the weather was finally with me and I had the time to put it in the lake . She started right up opened her up wot and flue like a dream then cut right out again. Now I have replaced everything under the flywheel points,condenser,coils,spark plug wires, and spark plugs, put in a inline filter and all new clamps,also O-rings on the needles to snug them up. First thing today I am going to the marina and buying a new tank and line if that does not solve the problem the only thing left is to replace the carb and I am not sure if that is the original one but I cannot think of any thing else to replace. Well Ill see what happens with the new tank and line later today.

Try pumping the squeeze bulb when the problem occurs to see if is related to fuel starvation. If it runs properly with manual pumping, the problem could be the hose, fuel connectors(o-rings), tank, or the fuel pump

Hello Bobby c , Well I got a new tank and line connectors it seemed to run a little better but I think it's the carb. I run great "wot'' then bogged again smoked like crazy at idle. I think I screwed up the low idle needle retainer. Because it has come out with the needle . Can this be replaced or secured some how. I haven't seen any piece like this in any rebuilding kit.

If it is the threaded sleeve that came out it is no problem.-It is held in place by the packing.--------------I have never had to " replace " a carburetor in 40 years of outboard repair.-------Usually the problem is elsewhere.

Does pumping the fuel primer bulb help when the motor starts to slow down??? Also...what fuel/oil ratio are you running? Is the "Smoke" you see blue(excessive oil) or is it white(steam...possible overheating)??

Hello racerone and bobbyc, I have fixed the surging guys it's not doing it now I had it on the lake sunday ran great 'wot' then the kids wanted to ski. So at idle it started smoking blue smoke and seemed like it was flooding out when I gave it the throttle stalled right out. The fuel mix I am using is 24.1 I can see that the water pump is working great plenty of water coming out so I don't think it over heating.I purchased a new tank and line, I did notice before I replaced it there where air bubble in the inline filter and it's not doing that now so I think that solved the air leak that someone said I might be having. Is there a special spark plug I should buy if I am stopping and going like this ? I am trying to teach the kids how to water ski and it's a task you move two feet and they dump so you have to swing around and try again it seem like I am idling a lot then full throttle I don't think it's burning all the fuel or to much is being dumped in. I have everything gaped right and all new . you guys have been great help I am almost there it seems to be running better every time I put it in. I am narrowing the problem slowly I know its something simple that I am missing just can't put my finger on it.

I don't believe you need to run the 24 to 1 ratio which was specified when that motor was new and SAE 30 non detergent automotive motor oil was the specified lubricant. With a modern TCW3 oil you should be able to run a 50 to 1 mixture with a lot less smoke, less plug fouling and better performance. I have a 1962 40 and I have run it at 50 to 1 for years without a problem using TCW(two cycle water cooled)oil. The smaller motors do not have as many needle bearings and may still need the richer oil mix but i believe yours is all needle bearings. Your motor may be a little different so I would wait for some other opinions before making the change. What type and heat range plugs are you running?

Have you inspected the fuel pump diaphragm??-------------Is the thermostat installed and working properly ???--------If it idles nice and then stalls on take off it may be too lean on the idle mixture.---------Also the carburetor may be opening too early , it must not open before the line on the cam makes contact with the throttle roller !

Hello Bobby and racerone , okay bob you say with the tcw3 oil I can run it at 50.1 mix don't you think that will burn up my motor " more oil is better then not enough right ?
racerone I have checked the fuel pump diapham and it looked okay to me I had not seen any rips or holes in it. On the thermostat I have not even looked at it. when I ran the engine last time on the lake it was running for a couple of hours, water was circulating great and I felt the engine block while it was running on both cylinders and it was warm to the touch "not hot" so I don't think that it is over heating.I think it had issues with sucking air from the tank and line so I replaced it now I think that it has to be just trying to fine tune the carb. I will see tomorrow I am on vacation for the next couple of weeks so I will have time to adjust the carbs and see what happens . I will post back my results

I want to thank everyone for there input into trying to figure out what went wrong on my motor . Well I had it out on the water after fine tuning and adjusting the carb again she runs like a dream . thank you again for all the help Paul